Cytochemical studies on endogenous peroxidase in conjunctival and corneal epithelial cells.

Endogenous peroxidase activity in conjunctival and corneal epithelial cells was studied cytochemically by the diaminobenzidine method. Many peroxidase-positive cells were found in the fornical conjunctiva. They were also seen, but less frequently, in the tarsal conjunctiva, limbus, and cornea. Three types of peroxidase-positive (cytochemically reactive) cells were differentiated besides goblet cells: (1) the most superficial cells with several reactive secretory granules (2) moth-eaten cells near the surface with abundant reactive microgranules, and (3) deeper cells with reactive microgranules and a few densely reactive granules. Some goblet cells shared the same characteristics with other types of cells. The relationship among these cells, functional differences between granules, and the function of peroxidase are discussed.